Such joints have the following characteristics: an outer joint part which comprises a first longitudinal axis LA as well as an attaching end and an aperture end which are positioned axially opposite one another, and which comprises first outer ball tracks and second outer ball tracks; an inner joint part which comprises a second longitudinal axis LI and attaching means for a shaft pointing towards the aperture end of the outer joint part, and which comprises first inner ball tracks and second inner ball tracks; the first outer ball tracks and the first inner ball tracks form first pairs of tracks which receive first balls; the second outer ball tracks and the second inner ball tracks form second pairs of tracks which receive second balls; and a ball cage is positioned between the outer joint part and the inner joint part and comprising circumferentially distributed first cage windows each accommodating one of the first balls and circumferentially distributed second cage windows each accommodating one of the second balls.
When assembling fixed joints it is common practice first to insert the outer joint part, the ball cage and the inner joint part into one another and then to insert the balls while over-articulating the joint, i.e. articulating the inner joint part and outer joint part relative to one another to such an extent that cage windows of the cage, with the cage guided on to half the articulation angle between the inner joint part and outer joint part, emerge from the outer joint part. When over-articulating the joint, any balls which have already been mounted and which are not positioned in the articulation plane and not in a plane extending through the axis of the ball cage perpendicularly to the articulation plane are displaced in the circumferential direction in their cage windows. The greater the articulation angle, the greater the circumferential length of the respective cage windows has to be. By increasing the length of the cage windows, the width of the webs between the cage windows is reduced. This results in a reduction in the strength of the cage, which is undesirable.
In connection with a constant velocity fixed joint whose pairs of tracks jointly widen towards the aperture, it is already known from U.S. Pat. No. 5,509,856 to propose a cage which comprises cage windows which are positioned opposite one another in a radial plane, which have a first shorter circumferential length as well as having cage windows whose centers are positioned outside said radial plane and outside a plane arranged perpendicularly thereto, having a second greater circumferential length.